In recent years, rimless type spectacles (to be also simply referred to as rimless spectacles hereinafter) are attracting a great deal of attention from the viewpoint of advantages such as a wide field of view and a light weight. In known rimless type spectacles with such advantages, lenses are held by providing recesses in the lens edge surfaces, inserting lens holding portions provided on lens holding members such as end pieces and a bridge into the recesses, and fixing the lens holding portions in position using an adhesive (resin) (see, for example, Japanese Patent No. 2854531 (Japanese Patent Laid-Open No. H07-230062), Japanese Patent Laid-Open No. 2001-209009, and Japanese Patent No. 3242879).
In a holding structure for spectacle lenses described in Japanese Patent No. 2854531, two blind holes are formed in the edge surface of each spectacle lens, lens holding portions each including two pin-shaped projecting portions are provided on lens holding members for a spectacle frame, and the lens holding portions are fixed in position using an adhesive while the pin-shaped projecting portions are inserted in the blind holes.
In holding structures for spectacle lenses described in FIGS. 4 to 6 of Japanese Patent Laid-Open No. 2001-209009, holes which have circular cross-sections and are elongated in the thickness direction of spectacle lenses are formed to run through the spectacle lenses in the thickness direction. In addition, edge surface holes with elongated-hole-shaped cross-sections are formed in the lens edge surfaces to communicate with the holes in the thickness direction. Connection portions with cross-sectional shapes corresponding to the edge surface holes are provided on lens holding members for a spectacle frame, and an adhesive is filled into the edge surface holes. After that, the connection portions are fitted into the edge surface holes to make the adhesive partially flows out to the holes in the thickness direction, thereby fixing the connection portions in position.
In a holding structure for spectacle lenses described in Japanese Patent No. 3242879, attachment holes are formed in the edge surfaces of spectacle lenses, and recesses are provided in the side walls of the attachment holes. Locking projections having protruding portions which fit into the recesses are provided on lens holding members, and are inserted into the attachment holes. After that, the locking projections are fixed in position using an adhesive while the protruding portions are locked in the recesses by sliding the locking projections.
In this manner, in rimless spectacles in which lenses are held by providing recesses in the lens edge surfaces, inserting lens holding portions into the recesses, and fixing the lens holding portions in position using an adhesive, the lens holding portions do not project to the optical surfaces of the lenses. Hence, these spectacles have a wide effective field of view, and lens surfaces which are easy to wipe. Also, in these spectacles, the lenses are held without screws etc., and therefore can be reliably held free from loosening and play.